Christopher ris



nirrnn firn'rns ATIENT tribe.

CHRISTOPHER RIS, OF BASLE, SWITZERLAND, ASSIGNOR TO JOHN R GEIGY & CO., OF SAME PLACE.

BLACK TRISAZO DYE.

SPECIFICATION forming part of Letters Patent No. 599,532, dated February 22, 1898. Application filed September 11, 1897. Serial No. 651,362- (Spec m s) To ctZZ whom it may concern.-

Be it known that I, CHRISTOPHER Rrs, doctor of philosophy, a citizen of the Republic of Switzerland, residing at Basle, in said Republic of Switzerland, have invented certain new and useful Improvements in Processes of Producing a Black Dyestuif, of which the following is a specification. 1

My invention refers to the production of a new black trisazo dyestuif, which is obtained by the combination of the tetrazo compound of paraphenylenediaminazobeta alpha amidonaphthol beta sulfo-acid (gamma acid) first in acid solution with one moleculeof a metadiamin, such as metaphenylenediamin, and afterward in an alkaline solution with one molecule of beta alpha amidonaphthol beta sulfo-acid.

The new dyestuft' possesses the following formula:

sonva \NH'Z O II sonael is produced in one of the well-known manamidoacetanilid with gamma acid or by. the

tetrazo compound of the saponified azo color amidonaphthol-s11lfo-acid in acid solution is for some hours in order to finish the formaprecipitate and the red color of the solution OH N N- ClOH ,N:N C H N:N- ClOlEL-NH Example: The paraphenylenediaminazobeta alpha amidonaphthol beta sulfo-acid 11ers by the saponification of the azo compound obtained by combination of diazotized parapartial reduction of the azo compound from diazotized paranitranilin and gamma acid. The

from fifteen kilograms of acetparaphenylenedialnin and twenty-four kilograms of gamma mixed with a solution of eleven kilograms of inetaphenylenediamin and the mass stirred tion of the intermediary compound. The lat ter separates in the form of an insoluble black disappears gradually. It shows an acid reaction. Then it is introduced in a solution of twenty-four kilos of beta alpha amidonaphthol beta sulfo-acid (gamma acid) with thirty-six kilograms of sodium carbonate in about five hundred liters of water. Then the mass is heated to to centigrade and the coloring-matter is filtered OE and dried. Instead of eleven kilograms of metaphenylenediamin there may also be used twelve kilograms of metatoluylenediamin. The first combination with the metadiamin can be carried out in a solution containing a mineral acid, such as sulfuric acid, hydrochloric acid, or an organic acid, such as acetic acid.

The coloring-matter forms a black powder soluble in water with black color, which by means of reduction becomes colorless. It is soluble in concentrated sulfuric acid with dark-blue color and scarcely soluble in alcohol. It dyes unmordanted cotton, wool, and silk in deep-black shades of great intensity. Cotton shades are faster to soap than most of the direct dyeing cotton colors.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. The process herein described of producing a new black trisazo color, which consists in combining the tetrazo compound of paraphenylenediaminazobeta alpha, amidonaphthol beta, sulfo-acid first in acid solution with one molecule of a metadiamin, (such as metaphenylenediamin,) and then in alkaline solution with one molecule of beta alpha amidonaphthol beta sulfo-aoid, substantially as set forth.

2. The black coloring-matter, obtained by combining the tetrazo compound of paraphenylenediaminazobeta alpha amidonaphthol bet-a sulfo-acid first with metadiamin and then with beta alpha amidonaphthol beta sulfo-acid, and having the following characteristics: being a black powder, soluble in water with black color, forming with reducing agents a colorless solution, soluble in concentrated sulfuric acid with a dark-blue color, scarcely soluble in alcohol, and dyeing unmordanted cotton, wool and silk in deepblack shades, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

CHRISTOPHER RIS.

IVitnesses GEORGE Grrronn, ALFRED NAPFLE. 

